The inventive concept relates to semiconductor devices. More particularly, the inventive concept relates to semiconductor devices having a conductive strip, namely, a power rail, by which a voltage source is connected to electronic elements of the device.
An electronic device such as a memory device, an integrated circuit, a smartphone, or a tablet personal computer (PC) includes a power rail along which operating voltages, provided by a voltage source, are supplied to electronic elements (e.g., transistors, memory cells, and flip-flops) of the electronic device, respectively. The stable supply of the operating voltages is essential to the reliability of the electronic device. In particular, an instantaneous drop in an operating voltage of an electronic element may cause the electronic element to malfunction. Voltage drop refers to the amount by which energy, supplied by a voltage source to an electrical circuit, is reduced by the passive elements of the circuit.
When a voltage source is connected to active or “electronic” elements of a circuit through a common conductive path such as that provided by power rails, the voltage (a first voltage) supplied to one of the electronic elements relatively close to the voltage source along the conductive path is higher than the voltage (a second voltage) supplied to another of the electronic elements further from the voltage source along the conductive path. Thus, in a case in which the voltage output from the voltage source abruptly changes, i.e., in the case of a voltage drop, a change in the second voltage may be greater than a change in the first voltage.
Accordingly, an electronic element of a circuit of an electronic device that is connected to a voltage source by a power rail and is relatively far from the voltage source along the conductive path provided by the power rail may be prone to malfunctions, or at the very least may be more prone to malfunctions than the other electronic element(s) of the circuit closer to the voltage source.